Oral Language Performance of Deaf and Hard-of-Hearing Students in Mainstream Schools.

In Hong Kong, students are expected to speak fluent Cantonese, Putonghua, and English. However, the curriculum does not include Cantonese studies, as children are expected to have already acquired Cantonese by the age of school entry. This study examined the language outcomes of Cantonese-speaking deaf or hard-of-hearing children who attend primary schools within the Hong Kong educational system and considered whether the system currently meets the needs of these children. The Hong Kong Cantonese Oral Language Assessment Scale, which comprises six subtests, was used to assess 98 children with mild to profound hearing loss. A regression analysis was used to examine the influences of various variables on oral language performance in these children. Notably, 41% of the participants had achieved age-appropriate oral language skills, while 18% and 41% exhibited mild-to-moderate or severe oral language impairment, respectively. The degree of hearing loss and the use of speech therapy were identified as significant negative predictors of oral language performance. The issues of a relatively late diagnosis and device fitting, as well as the very poor oral language outcomes, strongly emphasize the need for policy makers to reconsider the existing educational approaches and support for deaf or hard-of-hearing children.

Applying Rasch model analysis in the development of the cantonese tone identification test (CANTIT).

OBJECTIVE: Applying Rasch analysis to evaluate the internal structure of a lexical tone perception test known as the Cantonese Tone Identification Test (CANTIT). DESIGN: A 75-item pool (CANTIT-75) with pictures and sound tracks was developed. Respondents were required to make a four-alternative forced choice on each item. A short version of 30 items (CANTIT-30) was developed based on fit statistics, difficulty estimates, and content evaluation. Internal structure was evaluated by fit statistics and Rasch Factor Analysis (RFA). STUDY SAMPLE: 200 children with normal hearing and 141 children with hearing impairment were recruited. RESULTS: For CANTIT-75, all infit and 97% of outfit values were < 2.0. RFA revealed 40.1% of total variance was explained by the Rasch measure. The first residual component explained 2.5% of total variance in an eigenvalue of 3.1. For CANTIT-30, all infit and outfit values were < 2.0. The Rasch measure explained 38.8% of total variance, the first residual component explained 3.9% of total variance in an eigenvalue of 1.9. CONCLUSIONS: The Rasch model provides excellent guidance for the development of short forms. Both CANTIT-75 and CANTIT-30 possess satisfactory internal structure as a construct validity evidence in measuring the lexical tone identification ability of the Cantonese speakers.

An Application of Item Response Theory and the Rasch Model in Speech Recognition Test Materials.

PURPOSE: The purpose of this study was to describe an attempt to apply item-response theory (IRT) and the Rasch model to construction of speech-recognition tests. A set of word-recognition test items applicable to children as young as 3 years old-with any level of hearing sensitivity, with or without using hearing devices-was developed. METHOD: Test items were constructed through expert consultation and by reference to some established language corpora, validated with 121 participants with various degrees of hearing loss and 255 with typical hearing. IRT and the Rasch model were applied to evaluate item quality. RESULTS: Eighty disyllabic word items were selected in accordance with IRT. The speech-recognition abilities of the 376 young participants are reported. The IRT analyses on this set of data are also discussed. CONCLUSIONS: A new set of speech-recognition test materials in Cantonese Chinese has been developed. Construction of short equivalent lists may be performed in accordance with IRT item qualities. Clinical applications of this test tool in the particular language population are discussed.

Lexical tone perception in native speakers of Cantonese.

PURPOSE: This study aimed at investigating (1) tone perception development among typically-developing Cantonese speakers and (2) the hierarchy of tone perception difficulty among the 15 tone contrasts. METHOD: Two-hundred typically-developing children aged 3-10 and a group of 25 normal hearing adults were recruited. They were tested on a pool of 75-item calibrated recorded speech signals. Participants responded to each stimulus by pointing at the corresponding picture displayed on a computer screen from a choice of four. RESULT: There was a gradual increase in tone perception accuracy from children aged 3-6. After age 6, tone perception accuracy was similar to adults with an average error rate of 3-8%. The two tone contrasts that listeners consistently found difficult to distinguish were T2T5 (high-rising vs low-rising) and T3T6 (mid-level vs low-level). In addition, all children groups also showed difficulty in T4T6 identification (low-falling vs low-level). CONCLUSION: Tone perception is not error-free even among native Cantonese-speaking adults. Overall tone identification performance improved steadily from age 3 to age 6. Based on the participants' performance, a three-tier set of tone groups, with an increasing level of difficulty for identification, is proposed for rehabilitation purposes. These tone groups are (1) Easy: T1T2, T1T3, T1T4, T1T5, T1T6, and T2T3, (2) Medium: T2T4, T2T6, T3T4, and T4T5, and (3) Hard: T2T5, T3T5, T3T6, T4T6, and T5T6.

Cantonese tone production performance of mainstream school children with hearing impairment.

This study investigated the Cantonese tone production ability of children with hearing impairment studying in mainstream schools. The participants were 87 Cantonese-speaking children with mild-to-profound degrees of hearing loss aged 5.92-13.58 in Hong Kong. Most of the children were fitted with hearing aids (n = 65); 17 of them had profound hearing impairment, one who had severe hearing loss had cochlear implantation, and four who had mild hearing loss were without any hearing device. The Hong Kong Cantonese Articulation Test was administered, and the tones produced were rated by two of the authors and a speech-language pathologist. Group effects of tones, hearing loss level, and also an interaction of the two were found to be significant. The children with profound hearing impairment performed significantly worse than most of the other children. Tone 1 was produced most accurately, whereas tone 6 productions were the poorest. No relationship was found between the number of years of mainstreaming and tone production ability. Tone production error pattern revealed that confusion patterns in tone perception coincided with those in production. Tones having a similar fundamental frequency (F0) at the onset also posed difficulty in tone production for children with hearing impairment.

Comparison of Rater's reliability on perceptual evaluation of different types of voice sample.

OBJECTIVE/HYPOTHESIS: The objective of this study was to determine whether different types of voice samples affect rater reliability and which type of sample can be rated most reliably, with particular reference to two types of connected speech-passage reading and conversational speech. STUDY DESIGN: Prospective reliability study. METHODS: One hundred fifty voice samples from 40 speakers were presented to 14 speech pathologists experienced in managing voice disorders. Each speaker contributed three types of voice samples: sustained vowels, passage reading, and conversational speech. Ratings were made on four vocal parameters--overall severity, roughness, breathiness, and strain--on a 10-point equal-appearing interval scale. RESULTS: Differences in intrarater reliability across the three types of voice samples were noted. Higher intrarater reliability was achieved with connected speech than with sustained vowel samples. Interrater reliability showed no statistically significant difference across the three types but increased with the severity of dysphonia. CONCLUSIONS: This study reveals that raters give internally more reliable ratings for connected speech samples. Results also indicate that voices with severe disorders appear to be rated more reliably.

Gap junction intercellular communication in gliomas is inversely related to cell motility.

Gliomas are lethal because of local invasion into brain parenchyma. Glioma cells were isolated from different regions (white matter, gray matter and tumor core) of a glioma-bearing dog brain. Individual clonal cell lines were established from each area, and characterized for growth, migration and gap junctions. The regional clonal cell lines differed in rates and preferred substrate for migration. Cell lines generated from invaded white matter showed stimulated migration on collagen and variable migration on merosin, whereas migration of cell lines derived from invaded gray matter showed the reciprocal responses: stimulation on merosin and inhibition on collagen. Gap junctional communication showed significant degrees of variation between the different clones. A direct inverse relationship between the number of cells demonstrating gap junctional communication and migration rate of cells away from multicellular spheroids was evident. Glioma cells which have a reduced capacity to connect to each other have an accelerated migration rate onto autologous, glioma-derived matrix. These results suggest that invasive glioma cells suppress autologous cell-to-cell cohesion, partly evident as reduced formation of gap junctions. In addition, glioma cells were stimulated to migrate in a dose-dependant manner in response to epidermal growth factor (EGF) coincident with the reduction of Cx43 levels and increased serine phosphorylation. We speculate that in order for glioma cells to invade locally into brain parenchyma they must first detach from neighboring cells ("let go...let's go" paradigm of invasion).